Definetly see if the pump is pumping 1st. My 292 has a clear glass filter about halfway up the fuel tube going to the carb. My truck has never stumbled, AND I've never seen that filter full, EVER!! The pump may be bad, and if not, you might have a bad lobe for the pump. Even though you get fuel from the tank, the rubber hose might be weak, and collapses when vaccuum is applied by the pump, free flows otherwise.